Spark-plug.



W. J. OGORWMN,

SPARK PLUG. APPLICATION-FILED 28.10. |917- w-.w Specification of Letters Patent.

Patented liilay 2S, 191%.

Application vtiled.February 10, i917. Serial No. 147,761.

'l To all lwtom t may concer/n." A

Be it known that I, WILLIAM J. OGon- MAN, a citizen of the United States, and a resident oi New York, in the county of New York vand State of New York, have invented certain new and useful Im rovements .1n

Spark-Plugs, of which the ollowingis a specification. l

The invention relates to spark plugs `wherein provision is made for one or more artificial gaps located in the head oithe spark plug and in the circuit of the 1gn1t1on points of the plug as described in a prior Patent No. 1,228,958 dated .Iune 5th, 1917. In the form of this type of plug as described in my prior patent, the artificial spark gaps are located in chambers formed in the porcelain or insulation part of the plug which carries the wires leading to the Ignition gap.

-My present invention consists, among other things, inlocating the artificial gaps in a metallic protection formed by an extension of the clamp sleeve which clamps the porcelain in the metallic body or bushin and in extendin the porcelain up into said metallic protectlon, whereby the porcelain or insulation of the plug is completely protected and the desired artificial gaps are at the same time rovided for operatlon in the manner described in my prior patent.

My invention further consists in details of construction as hereinafter more particularly described and then specified in the claims.

Figure 1 is a vertical central section through a spark plug constructed in. accordance with my invention.

Fig. 2 is a side elevation of the same in reduced size.

Fig. 3 is a section andA side view onthe line 3 3 Fig. 2. y

Fig. 4 shows the porcelain or other insulating core removed from the plug.

Fig. 5 shows my improved clamp bushing removed from the plug.

Fig. 6 is a vertical section throu h the plug in a modified constructlon modi ed 1n construction to rovide an insulating barrier between the artlcialspark gaps.

Fig. 7 shows in detail a connection on the outside of the plug detached.

In the accompanying drawings, 1 indicates the insulating core of the plu wherein are located and insulated the leadgwires or connections 3, 4 which terminate in the spark points 5,'6 of the normal ignition gap. The usuall metallic body or shell of the spark plug is indicated at 2 and is provided, as usual, with a screw thread at 7 for attach- `ment of the spark plug to the engine.

8 indicates the threaded bushing or sleeve engaging the upper end of the shell or body 2 and adapted to clamp the porcelain or other core 1 in place. This sleeve in the usual construction of spark plug and in the form of plug described in my prior patent, is a short nut or bushing through which the porcelain or insulation of the core extends upwardly for attachment of the usual connections.v In my prior patent said porcelain is also rovided with the chambers in which the artificial spark gaps in the circuit of the sparking or ignition points are located, the sparking at said artificial gaps being visible through an opening inthe side of the insulation forming the upward extension of the insulating core.

In my present invention, however, the said metallic bushing extends up around the porcelain and terminates in a metallic socket or holder 9 which is provided as shown at u 10 with the observation openings through which the working of the artificial spark gaps may be observed. 11 indicates a block of insulating ber or hard rubber or other suitable insulating material in which the spark plug terminal posts are directly secured. Said body of insulation lhas a suitable chamber or chambers provided with openings which register with the openings 10 and the posts terminate in points in said chambers opposite the openings and in co eration with the points on the u per en s.

of the leading wires 3, 4 form arti cial gaps in the circuit of the ignition gap.

@ne of these, 13, serves for attachment of the leading wire 15 ot' the ignition circuit; the other terminal 12 has the return wire or strap connection 16 used as the ground wire grounded through the metal .of the engine b attachment xto the binding post or screwt l; secured to the metal body or shell of the plug. The socket or holder for the msulation l1 in the present form of my invention is shown as provided merely with tw'o straight sides between which the block of insulationl 11. is located and securedtin place by screws or other devices 18. The observation openings 10 are closed by wire gauze used as a safety device to prevent ignition of gas outside the plug.

23 indicates a reserve and einer ency s ark point attached to the-metal bo y'of 'tlie plug' and adapted to coperate with the point 6 t0 form an ignition gap in case of failure of the'main or principal ignition isi-gap to function properl or to form an emergency gap in case o 'need in a circuit between the wire 3 and the metal body of the plug and utilized by removal of the connection 16 and by employing the terminal 12 as the main or lead wire of the circult c as described' in my prior patent.

The body of insulation 11 preferably extends slightly beyond `the edges of the metallic holder or socket `9 and the edges of said insulation body 9 may be beveled or chamfered, as shown, between the metal edge of the body 9 and the outer surface of the insulation whereon the terminals 12, 13 are located.

The porcelain body or core 1 above referred to may be made of uniform cross-sectionup to the position of the artificial spark gap and above that point may rise in a web or barrier 19, as shown, extending if desired nearly up to the top wall of the insulation 11 forming, as shown, a part of the inclosure or chamberl in which the artificial f spark gaps are located. Said web Vor barrier 19prevents the passage of the spark across from one artificial gap to the other directly,

and compels passage of the current down to the lignition gap. The openings 10 may be ,flocated-xin both walls of the metal socket or v'liolderfor theinsulation and inline with One another. .Instead of forming a web or barrier 19 upon the end of the core 1 it may be formed upon the insulating body 11 as indicated in Fig. 6 where it is shown as a downward extension 19 from the top of said insulating body extending down between the spark gaps and approximately into contact with the end of the core 1. Y

As will be seen in my improved construction the porcelain forming the body or core `of the plug is completely protected by the metal forming an extension of the clamping bushing thereof and by the insulating liber or other insulating block fastened in said metallic extension and carrying the socket or holder registering with the openings in the holder terminals of the plug. Furthermore and inasmuch as ordinary insulatin fiber may be employed which may be rea ily worked, the terminals may be more readil fastened or secured in place than is possible where they are mounted directly in opposite sides of the porcelain head of'the porcelain core or body, which-is the construction described in mg prior atent.

I o not c aim specifically herein the arrangement of the barrier 19 illustrated in Fig. 6 and shown as a part of the insulating body 11 extending downwardly between 'the articial spark gaps and contacting with the end of the core 1 as this feature is claimed in my co-pending application for patent filed April 29th 1918.

What I claim as my invention is 1. In a spark plug of the character described, the combination of the insulating core, a metallic threaded bushing therefor having its upper end formed to constitute a o provided with observation openin 1n its sides, a chambered body of insulation mounted in said socket or holder and provided with openings in .its sides and a terminal post mounted directly in said insulating body and having a spark. point locatedy in said chamber in line with the' opening therein.

2. spark plug having two artiiical gaps located in the head of the plug and provided with an insulating core or porcelain having conducting wires or rods terminatin at their upper ends in points for two arti cial gaps, .the end of said porcelain being extended as a web or barrier between said points to form an insulating barrier between the gaps and prevent short circuiting of the ignition gap. A y 3. In a spark plu having two artificial gaps locate in the ead of the lug, con-, ducting wires or rods extending longitudinally through the insulating core or body and terminating at their up er ends in points for artificial gaps, sai gaps bein located in chambers the sidewalls of whic are formed in part by the metallic extension of the fastening bushing for the core and in partby a chambered block of insulating material having openings registerin 115 with openings in the metallic extension and spark plug terminals the points of which terminate inthe chambers formed in the insulation and opposite the upper ends of the said conductuig wires or rods as and for the purpose described.

4. In a spark plug, the combination substantially as described, of the insulating body or core provided with the conducting wires or rods terminatin at their upper ends in points for a spar gap or gaps, a

ieepee fastening bushing for said core extending up above the level of said terminal points, the metal of said extension being provided with openings opposite the wire terminals, and an insulating body fastened in said eX- tension and carrying the spark plug termi-v nals, the ends of which eoperate with the ends of said wires or rods to form artificial spark plug gaps opposite said openings and a web or barrier extending vertically be- 1Q tween the spark gaps.

Signed at New York, in the county of New York and State of New York, this 7th day of February A. D. 1917.

WILLAM J. OGRMAN.

Witnesses:

F. B. ToWNsnND, IRENE LnFkowrrz. 

